AFSK (Audio Frequency Shift Keying)

Audio Frequency Shift Keying (AFSK) is a method of transmitting digital data by changing the audio frequency of a signal. It uses two specific tones—each representing a different binary state (0 or 1). When sending data, the system switches between these tones to encode information. A leader or identifier often precedes the data, making it recognizable. Receivers interpret the changing audio frequencies to reconstruct the original digital message. AFSK is commonly used in amateur radio and data communication because it effectively transmits digital signals over audio channels like phone lines or radio waves.